TABLE 7.

Effect of overproduction of the enzymes of the AST pathway

Strain	Nitrogen sourcea	Generation time (min)	Enzyme activity, μmol/h/mg of protein (n)b, of:
			Dihydrolase	Desuccinylase	Transaminase	Dehydrogenase	Transferase
W3110	Arginine	296	1.5 ± 0.16 (3)	2.6 ± 0.10 (3)	5.4 ± 0.24 (3)c	0.48 ± 0.12 (2)	2.4 ± 0.4 (2)
W3110(pΔLC3-11)	Arginine	166	19.2 ± 0.39 (2)	16.6 ± 0.89 (2)	48.22 ± 0.28 (2)c	5.6 ± 0.6 (2)	20 ± 1.2 (2)
W3110	Aspartate	418	0.83 ± 0.17 (3)	1.3 ± 0.01 (3)	4.0 ± 0.3 (3)d	NDe	ND
W3110(pΔLC3-11)	Aspartate	245	6.16 ± 0.82 (2)	4.16 ± 0.38 (2)	11.2 ± 0.6 (2)d	ND	ND
W3110	Ammonia	103	0.03 ± 0.03 (2)	0.01 ± 0.01 (2)	2.6 ± 0.30 (3)d	ND	ND
W3110(pΔLC3-11)	Ammonia	97	0.09 ± 0.09 (2)	0.84 ± 0.12 (2)	3.8 ± 0.56 (2)d	0.24 ± 0.033 (2)	<0.8 (2)

^aCells were grown in minimal medium with 0.4% glucose and 0.2% of the indicated nitrogen source. 

^bSee footnote b of Table 2. 

^cThis measurement assessed only succinylornithine transaminase because arginine should repress acetylornithine transaminase. 

^dThis measurement may reflect both succinylornithine and acetylornithine transaminases because arginine is not present to repress the latter. 

^eND, not determined.